The present invention relates to folding joints and relates more particularly to a folding joint for the folding frame of a children's playyard of the foldable type.
Several foldable playyards have been known. In U.S. Pat. No. 4,934,025, John V. Mariol disclosed a center fold playyard having hinges coupling the rails of the upper horizontal support thereof at intermediate locations. The hinges are adapted to be rotated about their axes between a locked position wherein the playyard is secured for operation and use and an unlocked position wherein the upper rails thereof may be pivoted and the entire playyard collapsed upon the raising of the hub thereof. According to John V Mariol's disclosure, each hinge is comprised of two mating halves having offset circular sections which are joined together centrally by a pivot pin. Because the two hinge halves of each hinge are supported on a pivot pin only, the hinges or the rails thereto may be caused to deform when the playyard is secured for operation.
In U.S. Pat. No. 4,811,437, James and et. al. disclosed another structure of foldable playyard which utilizes latch mechanisms and spring means to connect the rails thereof. This structure is not durable in use because the spring means may become ineffective due to the happening of elastic fatigue problem.